EP1771713B1 - Balance ring and method for balancing a rotating component - Google Patents

Abstract

A balance ring for a component (1) rotating about a rotation axis (3), for example a tool holder for a rotating tool or else a machine spindle or the like, is proposed. The balance ring has an annular body (11) which is rotationally symmetrical with respect to an axis of rotational symmetry, a guide arrangement (13) guiding the annular body (11) in a radially movable but axially fixed manner on the component (1) with an axis of rotational symmetry essentially parallel to the rotation axis (3) of the component (1), and a plurality of adjusting elements (21) arranged in the circumferential direction of the annular body (11), preferably at equal angular distances from one another, radially supported between the annular body (11) and the component (1) and having a variable radial supporting length. The guide arrangement may be designed as an axially extending spring link arrangement or else as spring webs extending in the circumferential direction. Instead of the adjusting screws (21), electrically controllable actuators, such as, for example, piezoelectric elements or nanotube elements, may also be provided.

Description

The invention relates to a balancing ring and a method for balancing a rotating about a rotation axis component, in particular a tool holder or the like.

Rotating machine elements, such as eg with the drive spindle of a machine tool detachable tool holder for drills, milling cutters or the like, but also other rotating components, such as spindles or shafts, are conventionally balanced by means of balancing rings which are rotatable in pairs axially adjacent to each other concentric to the axis of rotation of the component are stored on this. The two balancing rings have eccentric center of gravity, whose dependent on the relative rotational position of the two balancing rings, resulting unbalance force is adjusted compensating opposite in balancing the component of the unbalance force of the component. By rotating the balancing rings relative to each other, the size of the resulting unbalance force of the balancing rings can be changed. By jointly twisting the two balancing rings, the direction of action of the resulting unbalance force can be changed. Such a device is eg in WO 94/16852 A disclosed.

Conventional pairs of balancing sets require precisely machined turning and guiding surfaces and require comparatively large space. In contrast, it is an object of the invention to provide an adjustable balancing ring with respect to the maximum imbalance of the balancing ring reduced dimensions.

• einen bezogen auf eine Rotationssymmetrieachse rotationssymmetrischen Ringkörper,
• eine den Ringkörper mit zur Drehachse des Bauteils paralleler Rotationssymmetrieachse radial beweglich, jedoch axial fixiert an dem Bauteil führende Führungsanordnung, und
• mehrere in Umfangsrichtung des Ringkörpers, vorzugsweise in gleichen Winkelabständen voneinander angeordnete, zwischen dem Ringkörper und dem Bauteil radial abgestützte Stellelemente mit veränderbarer radialer Abstützlänge.

The balancing ring according to the invention for a component rotating about an axis of rotation, in particular a tool holder or the like, comprises:

• one with respect to a rotational symmetry axis rotationally symmetric ring body,
• a parallel to the annular body with the axis of rotation of the component Rotational axis of symmetry radially movable, but axially fixed to the component leading guide assembly, and
• several in the circumferential direction of the annular body, preferably arranged at equal angular intervals from each other, radially supported between the annular body and the component control elements with variable radial support length.

Such a balancing ring is rotationally symmetrical as a whole, wherein a rotationally symmetrical design is to be understood here and below to mean a shape which, when rotated about the axis of rotational symmetry, can be brought to coincide with itself in angular steps of constant size. Such a shape can be produced very accurately and reproducibly. Unlike conventional balancing-ring pairs, which must be guided rotatably on this about the axis of rotation of the component, the balancing ring according to the invention is mounted centrally, but stationary in the circumferential direction of the component. The centric in its basic position to the rotational axis of the component annular body is guided by the Führunsganordnung in the circumferential direction on all sides radially deflectable on the component, wherein the angular position in which the annular body is deflected relative to the component radially and the extent of the radial deflection, the size and direction of the to compensate for a possible imbalance of the component determined unbalance force. Distributed in the circumferential direction, three or more adjusting elements are provided, which allow the ring body with the axis of rotation substantially parallel rotational symmetry axis, but to fix the size and direction of selectable eccentricity relative to the component.

The guide arrangement primarily ensures that the annular body is guided radially movably on the component with an axis of rotation of the component which is essentially parallel to the rotational symmetry axis. Suitable for this purpose are, for. B. arranged at an axial distance from each other, annular disc-shaped, axially normal to the axis of rotation extending annular disc surfaces, between which the annular body radially displaceable sitting. Of particular advantage, however, embodiments in which the annular body is fixed by means of an all-round radially deflectable spring link assembly on the component. This embodiment has the advantage that the annular body can occupy a concentric rest position relative to the rotational axis of the component, from which it can be deflected by means of the adjusting elements against the spring forces of the spring link arrangement. The ring body can automatically assume its centric rest position in this way, in which the imbalance of the component can be determined without this imbalance is distorted by eccentricities of the annular body. In a preferred embodiment, it is provided that the guide arrangement has a bearing on a cylindrical, concentric to the axis of rotation peripheral surface of the component retaining ring, which is connected via the on all sides radially deflectable spring link assembly with the annular body. However, the rest position may be eccentric to the axis of rotation of the component, since the eccentricity can also be considered in the balancing process.

The spring link arrangement, arranged along a concentric to the rotational axis of symmetry circle, comprise at least one substantially deflectable in the direction of the rotational axis of symmetry, radially deflectable spring element which - is axially connected - with its one end portion on the retaining ring and with its other end portion with the annular body. Such a spring link arrangement works on the principle of a parallel link arrangement with elastic links. The spring element may in this case be designed as a concentric, radially elastically deflectable sleeve relative to the rotational symmetry axis. The sleeve may have an annular closed sleeve wall, but it may also be divided in the circumferential direction by a plurality of axially extending slots in radially deflectable spring segments or spring bars. It is understood that the slot width may possibly be greater than the width of these spring segments in the circumferential direction.

In a variant, the spring link arrangement in the circumferential direction of Ring body distributes a plurality of pairs circumferentially extending spring bars, in particular a plurality of pairs of such spring bars comprise, which are held with their circumferentially adjacent ends in pairs on the ring body or in pairs on the retaining ring, and with their circumferentially remote ends of the other component, Retaining ring or ring body - be held. Advantage of the latter spring bars is that they allow comparatively long resilient web lengths, and in the radial displacement of the annular body are able to perform this exactly radially.

In the annular body, the spring assembly and the retaining ring may be separately manufactured components, which are subsequently combined to the balancing ring. In a preferred embodiment, however, the ring body, the spring assembly and the retaining ring are integrally formed in one piece, which improves the precision of the balancing ring.

The retaining ring may be a closed ring, which is slid and fitted accurately on a corresponding peripheral surface of the component. Conveniently, the retaining ring is attached by heat shrink technology to the component. It is understood that other conventional types of fastening can be used, for example by screwing on the component or by clamping using clamping screws. It is understood that the retaining ring on the component can also be soldered, welded or glued. It is also conceivable to provide the retaining ring with an internal thread, via which it can be screwed to the component.

However, the retaining ring may also be formed as a segmented ring whose segments are connected via the spring arrangement with the annular body. The retaining ring segments may have radial elastic properties, whereby the balancing ring can be held on the component via a radially resilient clamping seat. Again, however, the above-explained types of attachment can be used.

The actuators may be radially screwed setscrews. The screws can be screwed into a thread of the retaining ring and supported on the ring body. However, a variant in which the adjusting screws are arranged in screw holes of the annular body and are supported on the retaining ring or directly on the component is easier to produce and easier to adjust.

It is understood that, instead of radially movable adjusting elements, it is also possible for other adjusting elements which radially deflect the annular body to be provided. Suitable, for example, adjusting elements on the basis of inclined surface guides or handlebar guides, which allow a deviating from the radial movement adjusting movement of the link element. For example, the actuator may be formed as a wedge surface gear in which the wedge either in the circumferential direction, but preferably in the axial direction movable radially displaces the ring body. If the adjusting movement of such an actuating element runs parallel to the axis of rotation, then the adjusting elements do not influence the angular position of the unbalance vector of the annular body.

In the above-described actuators are mechanical transmission elements that allow a change in the support length. In a variant, it may be provided that the guide arrangement has a retaining ring resting on a cylindrical circumferential surface of the component concentric with the axis of rotation, on which the annular body is supported by a plurality of circumferentially distributed actuator elements having electrically controllable radial support length. Such actuators can be piezoelectric elements or nano-tube elements or the like, which change their spatial dimensions when an electrical voltage or a current is applied.

In a second aspect, the invention relates to a method for balancing a rotating about a rotation axis component by means of a attached to the component balancing rings. The method is characterized in that a balancing ring with a radially guided on the component ring body is mounted on the component, which is supported relative to the component via a plurality of circumferentially of the ring body, preferably at equal angular intervals from each other arranged adjusting elements with variable support length, that the component is driven in rotation together with the balancing ring about the rotation axis and a parameter representing the size and direction of the imbalance force occurring here is measured, and that depending on the measured unbalance parameter, the support length of the adjusting elements is changed, such that the ring body in one of the unbalance compensating radial position is shifted. Expediently, length adjustment information for the control elements is determined here as a function of the measured imbalance parameter. This can be done, for example, that is displayed on a display of the unbalance parameter measuring balancing machine by what value each of the control elements must be changed in its support length to compensate for the imbalance of the component. As far as adjusting screws are provided as adjusting elements, the display can indicate the number and direction of the revolutions by which each individual adjusting screw is to be turned.

Fig. 1

eine teilweise aufgebrochene Axialansicht eines Wuchtrings gemäß der Erfindung;

Fig. 2

einen Axiallängsschnitt des Wuchtrings, gesehen entlang einer Linie II-II in Fig. 1;

Fig. 3

eine teilweise aufgebrochene Axialansicht einer ersten Variante des Wuchtrings aus Fig. 1;

Fig. 4

einen Axiallängsschnitt der ersten Variante, gesehen entlang einer Linie IV-IV in Fig. 3;

Fig. 5

eine teilweise aufgebrochene Axialansicht einer zweiten Variante des Wuchtrings aus Fig. 1;

Fig. 6

einen Axiallängsschnitt durch die zweite Variante, gesehen entlang einer Linie VI-VI in Fig. 5;

Fig. 7

eine teilweise aufgebrochene Axialansicht einer zweiten Ausführungsform eines Wuchtrings;

Fig. 8

einen Axiallängsschnitt durch die zweite Ausführungsform, gesehen entlang einer Linie VIII-VIII in Fig. 7;

Fig. 9

eine teilweise aufgebrochene Axialansicht einer dritten Ausführungsform eines Wuchtrings, und

Fig. 10 bis 12

teilweise aufgebrochene Axialansichten von Varianten des Wuchtrings in Fig. 9.

In the following, embodiments of the invention will be explained in more detail with reference to a drawing. Hereby shows:

Fig. 1

a partially broken axial view of a balancing ring according to the invention;

Fig. 2

a Axiallängsschnitt the balancing ring, as seen along a line II-II in Fig. 1 ;

Fig. 3

a partially broken away axial view of a first variant of the balancing ring Fig. 1 ;

Fig. 4

a Axiallängsschnitt the first variant, as seen along a line IV-IV in Fig. 3 ;

Fig. 5

a partially broken axial view of a second Variant of the balancing ring Fig. 1 ;

Fig. 6

a Axiallängsschnitt through the second variant, as seen along a line VI-VI in Fig. 5 ;

Fig. 7

a partially broken away axial view of a second embodiment of a balancing ring;

Fig. 8

an axial longitudinal section through the second embodiment, as seen along a line VIII-VIII in Fig. 7 ;

Fig. 9

a partially broken away axial view of a third embodiment of a balancing ring, and

10 to 12

partially broken axial views of variants of the balancing ring in Fig. 9 ,

To balance one in the Fig. 1 and 2 generally designated 1, about a rotational axis 3 rotating component, such as a tool holder, a tool, a shaft or a work spindle of a machine, a radially adjustable balancing ring 7 is mounted on a circular cylindrical peripheral surface 5 of the component. The balancing ring 7 has an annularly closed retaining ring 9, with which it is held, for example, in shrink fit on the peripheral surface 5, and a radially adjustable balancing mass forming annular body 11, via a spring arm arrangement in the form of a coaxial to the rotation axis 3 radially between the retaining ring 9 and the ring body 11 extending sleeve 13 is connected to the retaining ring 9. The sleeve 13 has substantially an annular closed peripheral wall and is connected at its one end over its entire circumference by means of a radial web 15 with the retaining ring 9 and at its axially opposite end over its entire circumference by means of a radial web 17 with the annular body 11.

The sleeve 13 holds the annular body 11 in a concentric to the rotation axis 3 rest position from which the annular body 11 is radially resiliently deflected under radial elastic deformation of the sleeve 13 with substantially parallel to the axis of rotation 3 rotational symmetry axis. The sleeve 13 acts here in the circumferential direction on all sides in the manner of a parallel link arrangement.

In the circumferential direction, distributed at equal angular intervals sit in threaded holes 19 of the annular body 11, three radially outwardly accessible, radially screwed set screws 21, which pass through the sleeve 13 in through holes 23 and are supported on the outer periphery of the part fixed to the retaining ring 9. By screwing the screws 21, the annular body 11 can be adjusted from its concentric to the rotation axis 3 rest position with the axis of rotation 3 substantially parallel rotational symmetry axis radially in an eccentric position, the size and angular position of the eccentricity by the setting of the three screws 21 can be selected. The eccentricity of the annular body 11 is selected so that the imbalance force generated by the annular body 11 and possibly the sleeve 13 compensates for any imbalance of the component 1.

The unbalance of the component 1 is conventionally measured during rotation on a balancing machine according to size and angular position. The balancing machine determined according to the thus determined unbalance parameter required to compensate for the imbalance size and angular position of the eccentricity of the balancing ring 7 and expediently provides adjustment parameters for the screws 21, for example in the form of helical angle information for each of the screws 21. It is understood that the imbalance parameters not must necessarily be determined starting from the rest position of the ring body 11. Rather, any eccentric position of the annular body 11 is suitable, which then leads to setting values for the adjusting screws 21 which take into account the arbitrary starting position of the annular body 11.

In the embodiment described above, the retaining ring 9 is shrunk onto the peripheral surface 5 of the component 1 in the heat shrinking process, so that it is held by press-fit forces on the component 1. It is understood that the retaining ring 9 can also be otherwise attached to the component 1, for example, welded, soldered or glued can be. Also, the retaining ring 9 may be positively secured, for example by means of a thread on its inner circumference or else it may be fixed or screwed by clamping means, such as clamping screws or the like.

The retaining ring 9, the sleeve 13 and the ring body 11 are integrally connected integrally with each other and are preferably made of metal.

In the following, variants and configurations of the balancing ring are explained. Equal-acting components are each referred to with previously explained reference numerals and provided for discrimination with a letter. To explain the structure, the mode of action and possible variants, reference is made in each case to the preceding description.

The balancing ring 7 according to the Figures 1 and 2 has three offset by 120 ° to each other angularly offset on the ring body 11 radially screwed screws 21. Die FIGS. 3 and 4 show a variant of a balancing ring 7a, in contrast to the balancing ring 7 of the Figures 1 and 2 four by 90 ° from each other angularly offset screws 21 a radially screwed to its ring body 11a includes. The adjusting screws 21a are also not supported on the retaining ring 9a, but pass through openings 25 of the retaining ring 9a and are based directly on the peripheral surface 5a of the component 1a.

The FIGS. 5 and 6 show another variant of the basis of the Figures 1 and 2 explained balancing ring 7, the retaining ring 9 is closed in a ring. In contrast, the retaining ring 9b of the balancing ring 7b of FIGS. 5 and 6 divided by a plurality of slots 27 into segments 29 which bear radially resiliently on the circumference 5b of the component 1b and fix the balancing ring 7b on the component 1b. The slots 27 may be limited to the retaining ring 9b. But you can also in the radial webs 15b and possibly the sleeve 13b and the radial web 17b extend into, as at 31 in FIG. 6 is indicated. Although the adjusting screws 21 b can also be supported directly on the component 1 b, they are preferably supported on the segments 29 in order to improve the fixation of the balancing ring 7 b on the component 1 b. It is understood that instead of in FIG. 5 shown three screws 21 b and more screws can be present.

In the embodiments of the Figures 1-6 the control elements are designed as manually operated screws. The FIGS. 7 and 8 show the variant of a balancing ring 7c, in which the adjusting elements are designed as electrically controllable actuators 21c, which change their radial dimensions in not shown supply of electrical signals. The actuators 21c are, for example, piezoelectric elements or nano-tube elements or the like. The actuators 21c sit in guide openings on the outer jacket of the retaining ring 9c on the one hand and on the inner surface of the annular body 11c on the other hand and at the same time take over the radial and axial guidance and fixation of the annular body 11c on the retaining ring 9c. The guide openings can, as in the FIGS. 7 and 8 illustrated, may be formed as annular grooves 33 and 35, in which the actuators 21c are fixed in each case at equal angular intervals. It is understood that electrically controllable actuators can also be used in the previously explained and the following embodiments. The retaining ring 9c can be secured in the manner explained above on the outer circumference 5c of the component 1c.

In the preceding on the basis of Figures 1-6 variants explained determines the spring characteristics in the first place, the axial length of the sleeve forming the spring arm assembly. The dimensions of the balancing ring in the axial direction can be kept small if, as in the embodiments explained below, the resilient length of the spring arm arrangement does not extend in the axial direction but in the circumferential direction of the annular body. In the circumferential direction is comparatively much space for the accommodation of the Spring link arrangement available. So shows FIG. 9 a variant of a balancing ring 7d, the annular body 11d are connected via a plurality of pairs of circumferentially extending spring bars 13d with the individual segments 9d of a circumferentially divided into a plurality of segments retaining ring. The retaining ring consists in the illustrated embodiment of three segments 9d, which follow each other in the circumferential direction to form gaps 37, wherein in threaded openings 19d of the annular body seated, radially screwed screws 21 d engage through these gaps 37 and are supported directly on the outer periphery 5d of the component 1d.

The pairs of spring webs 13d, which are formed substantially as circumferentially curved leaf springs, are connected at their ends remote from each other to the circumferential ends of one of the retaining ring segments 9d. The adjacent ends of the spring bars 13 of the pair are connected centrally between circumferentially successive set screws 21 d with the ring body 11 d.

The retaining ring segments 9d may be fixed on the component 1d due to their inherent elasticity; but they can also be otherwise secured, for example glued or soldered or screwed.

The balancing ring 7e of the FIG. 10 differs from the growth ring 7d the FIG. 9 essentially only in that the retaining ring 9e is formed as a ring-shaped closed retaining ring, which is similar to the variant of the passage for the passage of the screws 21e FIGS. 3 and 4 , with through holes 25e understand, through which the set screws 21 e can be supported directly on the outer periphery 5e of the component 1e. The spring bars 13e are each connected in the circumferential direction on both sides of each screw 21e with the retaining ring 9e.

In the FIG. 11 shown variant of a balancing ring 7f differs from the balancing ring 7d in FIG. 9 only in that the segmented retaining ring forming segments 9f are not connected at their opposite ends with the circumferentially extending spring bars 13f in pairs, but each in its central region between two circumferentially sequential screws 21f. The spring bars 13f of each pair are accordingly connected to the ring body 11f at their circumferentially distal ends. Also in the variant of FIG. 11 The retaining ring segments 9f form gaps 37f through which the adjusting screws 21f bear directly on the outer circumference 5f of the component 1f.

FIG. 12 shows a variant of a balancing ring 7g, in which the retaining ring 9g according to the variant of FIG. 10 is closed annularly, in turn, the set screws 21g pass through through holes 25g and are supported directly on the outer circumference 5g of the component 1g. In contrast to the growth ring 7e the FIG. 10 However, in the balancing ring 7g, between two circumferentially successive setscrews 21g arranged in pairs spring bars 13g connected with their adjacent ends to the retaining ring 9g, while the mutually remote ends are axially connected on both sides of the through holes 25g with the ring body 11g.

It is understood that the screws 21g and 21 e in the FIGS. 10 and 12 shown balancing rings can also be supported on the annular closed retaining ring, as for the balancing ring 7 in the Figures 1 and 2 was explained. The fixing of the retaining rings on the component can be done by shrinking, gluing, welding, as explained above.

Claims (16)

1. A balance ring for a component (1) rotating about a rotation axis (3), in particular a tool holder or the like, comprising:

   - an annular body (11) which is rotationally symmetrical with respect to an axis of rotational symmetry,

   - a guide arrangement (13, 21c) guiding the annular body (11) on the component (1) in a radially movable but axially fixed manner with an axis of rotational symmetry essentially parallel to the rotation axis (3) of the component (1), and

   - a plurality of adjusting elements (21) arranged in the circumferential direction of the annular body (11), preferably at equal angular distances from one another, radially supported between the annular body and the component and having a variable radial supporting length.
2. The balance ring as claimed in claim 1, characterized in that the guide arrangement has a retaining ring (9) which bears against a cylindrical circumferential surface, concentric to the rotation axis, of the component (1) and which is connected to the annular body (11) via a spring link arrangement (13) radially deflectable universally.
3. The balance ring as claimed in claim 2, characterized in that the spring link arrangement (13) is arranged along a circle concentric to the axis of rotational symmetry and comprises at least one radially deflectable spring element (13) which extends essentially in the direction of the axis of rotational symmetry and which - as viewed axially - is connected with its one end region (15) to the retaining ring (9) and with its other end region (17) to the annular body (11).
4. The balance ring as claimed in claim 3, characterized in that the spring element is an elastically deflectable sleeve (13) concentric to the axis of rotational symmetry.
5. The balance ring as claimed in claim 4, characterized in that the sleeve (13) is subdivided in the circumferential direction into radially deflectable spring segments by a plurality of axially running slots (27) or apertures.
6. The balance ring as claimed in claim 2, characterized in that the spring link arrangement, in a distributed manner in the circumferential direction, comprises a plurality of pairs of spring webs (13d-g) which extend in the circumferential direction and which are held with their ends which are adjacent in the circumferential direction in pairs on the annular body (11d-g) or in pairs on the retaining ring (9d-g) and are held with their ends which are remote in the circumferential direction on the other respective component - retaining ring (9d-g) or annular body (11d-g).
7. The balance ring as claimed in one of claims 2 to 6, characterized in that the annular body (11), the spring arrangement (13) and the retaining ring (9) are integrally formed in one piece.
8. The balance ring as claimed in one of claims 2 to 7, characterized in that the retaining ring (9, 9a, e, d) is designed as a closed ring.
9. The balance ring as claimed in claim 8, characterized in that the retaining ring (9) can be shrunk onto the component (1).
10. The balance ring as claimed in one of claims 2 to 7, characterized in that the retaining ring (9b, d, f) is designed as a segmented ring, the segments of which are connected to the annular body (11b, d, f) via the spring arrangement (13b, d, f).
11. The balance ring as claimed in one of claims 1 to 10, characterized in that the adjusting elements are designed as adjusting screws (21) which can be screwed down radially.
12. The balance ring as claimed in claim 11 in combination with one of claims 2 to 10, characterized in that the adjusting screws (21) are arranged in screw holes (19) of the annular body (11) and are supported on the retaining ring or directly on the component.
13. The balance ring as claimed in claim 1, characterized in that the guide arrangement has a retaining ring (9c) which bears against a cylindrical circumferential surface, concentric to the rotation axis (3), of the component (1c) and on which the annular body (11c) is supported via a plurality of actuators (21c) which are distributed in the circumferential direction, form the adjusting elements and have a controllable radial supporting length.
14. The balance ring as claimed in claim 13, characterized in that the actuators are designed as piezoelectric elements or nanotube elements.
15. A method for balancing a component rotating about a rotation axis (3) by means of a balance ring (7) attached to the component, characterized in that a balance ring (7) having an annular body (11) guided on the component (1) in a radially movable manner is attached to the component, which balance ring (7) is supported relative to the component (1) via a plurality of adjusting elements (21) arranged in the circumferential direction of the annular body (11), preferably at equal angular distances from one another, and having a variable supporting length, in that the component (1) together with the balance ring (7) is rotationally driven about the rotation axis (3), and an unbalance parameter representing the size and direction of the unbalance force occurring in the process is measured, and in that the supporting length of the adjusting elements (21) is varied as a function of the measured unbalance parameter in such a way that the annular body (11) is displaced into a radial position compensating for the unbalance force.
16. The method as claimed in claim 15, characterized in that length-setting information for the adjusting elements (21) is determined as a function of the measured unbalance parameter.

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